Osaka-based Capcom has filed a lawsuit against Koei Tecmo Games in Osaka District Court seeking roughly 980 million Japanese yen (~$9.4 million USD) for patent infringement, according to a report from the Japanese news outlet Sankei interpreted by Siliconera.

Capcom seems to be alleging that Koei Tecmo has published a number of games, including multiple titles in the Dynasty Warriors and Samurai Warrios franchises, which infringe on a 2002 Capcom patent governing how a company distributes additional content to people who own one of its games.

The full details of the patent in question are yet unclear, but it's likely that Capcom is referring to the disc-based expansion packs available for some Koei Tecmo PlayStation titles.

Capcom claims Koei Tecmo earned roughly 97 billion Japanese yen in profits on sales of infringing titles, and it seeks damages commensurate with the fees it believes Koei Tecmo should have paid to license the technology as well as a suspension on further sales of select Koei Tecmo games.